Endless type carrier belt having type-receiving pockets in an edge thereof

ABSTRACT

An endless character belt for an on-the-fly printer having drive teeth arranged on the inner circumference thereof and pockets located in an edge of the belt for receiving type members perpendicular to the plane of the belt. The type members may be held in place by arcuate projections arranged on the interior of the pockets for applying an affixing force to the type members.

United States Patent Hepner et a1.

[54] ENDLESS TYPE CARRIER BELT HAVING TYPE-RECEIVING POCKETS IN AN EDGE THEREOF [72] Inventors: Neal Hepner, Birmingham; Albert C.

Williamson, Plymouth, both of Mich. [73] Assignee: Burroughs Corporation, Detroit,

. Mich. v [22] Filed: Feb. 4, 1970 [21] Appl. No; 8,563

[52] US. Cl. ..l0l/lll, 101/368, 101/60 [51] Int. Cl. .;.B4lj l/26 [58] Field of Search ..101/93, 110, 11-1, 368, 378, 101/377, 379, 60, 380, 381

[56] References Cited 5 1 UNITED STATES PATENTS 2,918,865 12/1959 Wooding ..l01/93 2,950,048 8/1960 Luhn ..235/61 3,041,965 7/1962 Sasaki ..l0l/381 X 1,798,177

3/1931 Spielman ..101/380 11 1 3,683,802 1 Aug. 15, 1972 1,190,497 Willard .I ..10l/38l Antonucci .Q 101/93 C Primary Examiner-William B. Penn' Assistant Examiner-E. M. Coven Altorney-Kenneth L. Miller and Charles S. Hall 571 ABSTRACT K An endless character belt for an on-the-fly printer havingdrive teeth arranged on the inner circumference thereof and pockets located in an edge of the belt for receiving type members perpendicular to the planeof the 'belt. The type members may be held in place by arcuate projections arranged on the interior of the pockets for applying an affixing force to the type members.

4 Claims, 6 Drawing Figures PATENTEDAUG 1 5 I972 3, 3, 02

. FIG. I.

mvsmons NEAL HEPNER 8 ALBERT C. WILLIAMSON AGENT 'IIIIIIIIIIIIIII/ ENDLESS TYPE CARRIER BELT HAVING TYPE- RECEIVING POCKETS IN AN EDGE THEREOF BACKGROUND OF THE INVENTION The invention relates to printing members for onthe-fly printers which selectively print characters arranged on the printing member and more particularly to printing members of this type which form an endless band.

In the prior art, generally U-shaped type members having a character arranged thereon have been clamped partially around an endless belt having drive teeth on the inner circumference of the belt. The type characters are positioned on the face of the belt opposite the face which bears the drive teeth and are parallel to the plane of the belt. An example of this type of character belt is shown in US. Pat. No. 3,402,657 is sued to Potter et al on Sept. 24, 1968. This form of belt is relatively heavy due to the large amounts of metal required to form the type members. Since the type members of these prior art belts are only clamped to the belt they tend to move laterally on the belt and alter their dimensional positioning, thereby resulting in an inaccurate alignment of the characters in the printer. Also the belt is difficult to assemble and therefore is relatively costly to manufacture.

With a continuing necessity for faster printing operations, it is desirable to utilize a character belt having type members positioned at intervals of 0.1 inch instead of the 0.2 inch spacing which is commonly used by prior art belts. The problems of weight, lateral movement of type members and assembly become much more severe when type members are used at more closely spaced intervals.

Therefore, it is an object of this invention to lighten an endless character belt for a high speed printer having type members affixed thereto and thereby lessen the tension on the belt at a given speed of operation.

A further object of this invention is to increase the dimensional stability of the type members on an endless character belt for an on-the-fly printer.

A still further object is to simplify the assembly process for affixing the type members to an endless character belt.

Another object of this invention is to increase the flexibility of an' endless character belt to facilitate the rounding of small-diameter drive gears.

In the present invention an endless belt is provided having drive teeth on the inner circumference of the belt and pockets arranged across the width of the belt for receiving type members in the edge thereof. In this arrangement the type characters are perpendicular to the plane of the belt. Arcuate projections may be provided on the interior of the pockets for applying an affixing force to a type member which is inserted in the pocket. Transverse relief channels may be provided between adjacent pockets to increase the flexibility of the belt in rounding small-diameter drive gears.

The foregoing and other aspects of the invention will be apparent from the following detailed description of the preferred embodiment of the invention shown in the drawings in which:

FIG. 1 is a broken schematic view of an endless character belt and affixed type members of the present invention as used in an on-the-fly printer.

FIG. 2 is an enlarged view of a portion of the endless character belt and associated type member shown in FIG. 1.

FIG. 3 is a vertical cross section of the endless character belt and associated type member taken along line 3-3 in FIG. 2.

FIG. 4 is a horizontal cross section of the endless character belt, without the associated type member, taken along line44 in FIG; 2.

FIG 5 is an isometric view of a portion of the endless character belt of the present invention.

FIG. 6 is an isometric view of a modified embodiment of the endless character belt of the present invention.

Referring to FIG. 1, an embodiment of the present invention positioned in a printer for movement in a vertical plane includes an endless character belt 11 arranged on a drive gear 13 and an idler gear 15. The belt is formed of a flexible material such as rubber or some suitable synthetic material and may be of any desired length as indicated by the broken lines in the drawing. Reinforcement fibers'may be provided in the belt to give strength to the belt and aid in resisting tension forces that are applied during operation of the belt.

The endless belt 11 has drive teeth 17 arranged on its inner circumference for engaging the gears 13 and 15. In the preferred embodiment, a driving force is applied to the drive gear 13 by a drive shaft 19, thereby causing the belt to move while the idler gear 15 rotates freely about an idler shaft 20. If desired, both gears can receive a driving torque for moving the belt 1 1.

Type members 21 are carried by the endless belt in perpendicular relation to its plane in equally spaced apart positions along one side edge of the belt in a manner to be detailed hereinafter. A row of type hammers (not shown) is positioned in opposed relation to the type characters exposed along the side edge of the top section of the belt. A record medium such as a sheet or web of paper is disposed between the row of type hammers and the printing type carried by the top section of the belt 1 I. One type hammer is provided for each column to be printed on the record medium. As the belt 11 is continuously advanced by the drive gear 13, the printing type 21 in the belt is moved along the row of type hammers.

An electronic control unit causes a type hammer to strike the paper and cause it to impact a passing type member when the character to be printed in a column is aligned before the hammer provided for that column. The electronic control circuitry generates synchronizing signals which indicate the particular character appearing before a type hammer, as is known in the art. When the circuitry detects that the desired character to be printed in a column is before the type hammer for that column, the hammer is energized and drives the paper against the desired character thereby printing the character in that column.

For example, assume that the alphabetical character A is to be printed in columns 2-, 6 and 14 of the record medium. As the belt 11 is moved continuously A type member 26 on the paper. Similarly, when the A" type member 26 becomes aligned with columns 6 and 14 the type hammers for these respective columns will print the A character. The other characters to be printed on a line of the record medium are printed in a similar manner. The record medium is then stepped upward to align the next line to be printed with the row of hammers and the printing of the next line continues in the same manner.

Various characters may be formed on the type members 21 and arranged in any desired sequence in the belt 11 to form a set of characters for presentation to the type hammers. Typically, a set of characters will comprise the 26 alphabetical characters, the numerals zero through nine, and various punctuation or other symbols. In some instances, it is desirable to have several complete sets of characters arranged on the belt 11. Thus, in the case where two complete sets of characters are provided, two sets of characters will pass before the type hammers during each revolution of the belt.

Since the axis of the type member is perpendicular to the plane of the belt 11, the striking force of a type hammer is distributed across the width of the belt. A rear support member 25 may be provided to resist the striking force and retain the belt 11 in place when a type hammer strikes the belt. Transverse relief channels 23 are provided between adjacent type members to give increased flexibility to the belt 11 when rounding small-diameter drive gears.

An enlarged view of the belt 11 and associated type member 27 is shown in FIG. 2. The type member 27 is substantially centered on drive tooth 33 and has the alphabetic character embossed thereon, although any desired character may be used, as previously mentioned. A transverse relief channel 29 is shown between the type member 27 and adjacent type member 31.

A vertical cross-section of the belt 11 and the type member 27 taken along the line 3-3 of FIG. 2 is shown in FIG. 3. The type member 27 has a rectangular shaft 34 which is embedded in the belt and includes a flattened head or face 35 having an embossed design 37 which forms the alphabetic character 0 although any desired character may be embossed on the face 35. The face 35 is larger than the rectangular cross-section of the shaft 34 and rests against the edge of the belt 1 1. Thus, the face 35 serves as a stop when the type member is inserted into the belt 1 1.

A cross section of the character belt 11, without the type member 27, taken along line 4-4 of FIG. 2 is shown in FIG. 4. The belt 11 includes a pocket 39 for receiving the rectangular shaft 34 of the type member 27 which type member is not shown in FIG. 4. In the preferred form, the walls of the pocket have arcuate projections 41 protruding from opposing walls of the pocket 39 to provide a narrowed pocket width which is less than the corresponding dimension of the rectangular shaft of a type member. The projections 41 apply an affixing force component to the rectangular shaft of a type member inserted into the pocket 39 and retain the inserted type member in the belt 11. The projections may be formed of the same material as the belt or they may be formed of some other flexible material and then fastened to the opposing walls of the pocket 39. It is apparent that the projections 41 need not be arcuate but may be of any desired shape.

In assembly of the character belt the type members are placed in the mouth of the pocket 39 and a compressive force is applied to the type member to drive it into the pocket. This procedure may be performed by hand or may be accomplished automatically by machine. It can be seen that as a result of the unique construction of the character belt and the pockets, the printing member of the present invention may be easily assembled.

It has been discovered that the arcuate projections 41 acting alone apply sufficient force to retain a type member in place. However, if desired, a type member may additionally be bonded to the walls of the pocket 39 with a suitable adhesive. When the arcuate projections 41 are used in combination with an adhesive, the projections serve to retain a type member in place while the adhesive is curing and forming a bond with the walls of the pocket 39. An alternate means of affixing a type member in the pocket is to utilize solely the adhesive to bond a type member to the pocket.

FIG. 5 shows an isometric view of a portion of the character belt depicted in FIG. 1. The type members 21 are positioned in the outer edge of the belt 11 above the drive teeth 17 shown on the inner circumference of the belt. Transverse relief channels 23 are provided between adjacent type members. As previously mentioned, the channels 23 allow the belt to flex freely when rounding small-diameter drive gears. However, if the character belt is sufficiently flexible for the diameter of drive gear being used, the relief channels may be omitted as shown in FIG. 6 where the same numerals indicate the same parts as in FIG. 5. If desired, when the relief channels are not provided between adjacent type members in the belt 11', the type members may be located at more closely spaced intervals along the character belt instead of being substantially centered on a one of the drive teeth as shown in the drawings. In this manner even closer spacing of the type members can be achieved.

A character belt constructed according to the concept of the present invention is capable of being very light in weight. As an example, a character belt of 48 inch length with type members located at intervals of 0.1 inch would have 480 type members. If the type members are made of steel, they would weigh a total of only 0.44 pounds. The same number of steel type members used with prior art character belts would weigh several times as much. This saving in weight is achieved by the unique construction of the present invention in which pockets in the character belt are utilized to retain the character bearing type members perpendicular to the plane of the character belt. This construction allows the use of type members which are substantially reduced in size when compared to prior art type members.

What is claimed is:

1. A character bearing member for on-the-fly printers utilizing print hammers, which selectively print characters successively arranged thereon comprising:

an endless belt formed of a band of flexible material,

relatively wide with respect to its thickness, said belt having a plurality of pockets extending substantially across the width and opening only on an edge thereof, at least one edge of said belt defining a plane; and

a face on one end thereof, said face being larger than the cross section of said shaft and having a character embossed thereon and said shaft being inserted in one of said pockets.

4. The character bearing member of claim 3 wherein said pockets have arcuate projections on the interior thereof for applying an affixing force to said insertahlc shaft of said type members. 

1. A character bearing member for on-the-fly printers utilizing print hammers, which selectively print characters successively arranged thereon comprising: an endless belt formed of a band of flexible material, relatively wide with respect to its thickness, said belt having a plurality of pockets extending substantially across the width and opening only on an edge thereof, at least one edge of said belt defining a plane; and type members individually insertable in each of said pockets for presenting printing surfaces to said print hammers, the impact of said hammers being substantially perpendicular to said plane.
 2. The character bearing member of claim 1 wherein said belt includes transverse relief channels between adjacent ones of said pockets in said belt.
 3. The character bearing member of claim 1 wherein said type member comprises a rectangular shaft having a face on one end thereof, said face being larger than the cross section of said shaft and having a character embossed thereon and said shaft being inserted in one of said pockets.
 4. The character bearing member of claim 3 wherein said pockets have arcuate projections on the interior thereof for applying an affixing force to said insertable shaft of said type members. 